Try adding the following CSS to your Quick CSS (located under the Styling Tab in the theme options) or the custom.css file in the css folder of your theme files:

#top .main_menu ul.menu li a {
color: black;
}

If your theme options aren’t saving you can try disabling all active plugins and drop ins and then seeing if you are able to save then. If not, re-download the theme from your downloads on theme forest to make sure you are up to date as well as there aren’t any issues with the theme files.